The goal of this proposal is to investigate the principles and mechanisms by which the central nervous system organizes the regulation of body temperature. By observing and analyzing both the single unit activity in the PO/AH area and the thermoregulatory responses of conscious animals to changes in peripheral and central temperatures after ablations of the ascending monoaminergic pathways, we hope to produce two tangible results. a) A more full understanding of the nature and mechanism of PO/AH thermosensitivity and b) Information on the role of the lower brainstem nuclei in transmitting peripheral thermal input into the hypothalamus and in modulating thermoregulatory functions. Protocols for the testing of stated hypotheses in the proposal are outlined. BIBLIOGRAPHIC REFERENCES: Inhibition of thermoregulatory outflow in conscious rabbits during periods of sustained arousal. J.T. Stitt. J. Physiol. (London) 260, 31-32P. 1976. Thermoregulatory responses of rabbits treated by the monoaminergic neurotoxins 6-hydroxydopamine and 5, 7-dihydroxytryptamine, J.T. Stitt and M.T. Lin, Can. Physiol. 8, 65, 1977.